gruntでexpressを起動すると文字化けするのを解消 ref: http://qiita.com/TsuyoshiMIYAMOTO/items/f7cf071f47b7190f7b01

file0.js

  var child = spawn(cmd, args, opts.opts);
  var stdout = [];
  var stdoutLength = 0;
  var stderr = [];
  var stderrLength = 0;
  if (child.stdout) {
    child.stdout.on('data', function(buf) {
        stdout.push(buf);
        stdoutLength += buf.length;
    });
  }
  if (child.stderr) {
    child.stderr.on('data', function(buf) {
        stderr.push(buf);
        stderrLength += buf.length;
    });
  }
  child.on('close', function(code) {
    var so = Buffer.concat(stdout, stdoutLength);
    var se = Buffer.concat(stderr, stderrLength);
    callDone(code, so.toString(), se.toString());
  });
  return child;